Criteria for low bp is clinical and not based on values. But a systolic bp around 110 is normal . And diastolic around 80 is normal. A single lower-than-normal reading is not cause for alarm, unless you are experiencing any other symptoms or problems. If you experience any dizziness, lightheadedness, nausea or other symptoms, it’s a good idea to consult with your healthcare provider.

There's no low BP in normal individual. If symptoms of giddiness,nausea , vomiting or any condition when your BP down by 30 percent of your normal BP. For female systolic BP 90 to 110 is ok